The role of the central nucleus of the amygdala in nociception and aversion

&NA; The role of the central nucleus of the amygdala in nociception ‐ conditioned and unconditioned aversion ‐ was studied. Rats received microinjection of vehicle or the N‐type Ca2+ channel blocker Ω‐conotoxin GVIA (0.2 &mgr;g/250 nl) into the central amygdaloid nucleus prior to intra‐plantar injection of formalin, ultrasound exposure or immediately prior to the acquisition phase of an aversive conditioning trial. Intra‐amygdala Ω‐conotoxin GVIA resulted in an earlier onset of nociceptive response to formalin and increased nociceptive behaviour during the first 5min. Ω‐Conotoxin GVIA significantly reduced conditioned freezing behaviour with no effect on ultrasound‐induced unconditioned aversive behaviour. These data indicate that N‐type Ca2+ channels in the central amygdaloid nucleus play a role in mediating behavioural responses to nociceptive and conditioned aversive stimuli. NeuroReport 14:981–984 © 2003 Lippincott Williams & Wilkins.

[1]  W. A. Prado,et al.  Role of PAG in the antinociception evoked from the medial or central amygdala in rats , 2001, Brain Research Bulletin.

[2]  M. Behbehani,et al.  An electrophysiological characterization of the projection from the central nucleus of the amygdala to the periaqueductal gray of the rat: the role of opioid receptors , 1995, Brain Research.

[3]  P. Shinnick‐Gallagher,et al.  Dihydropyridine- and neurotoxin-sensitive and -insensitive calcium currents in acutely dissociated neurons of the rat central amygdala. , 1997, Journal of neurophysiology.

[4]  C. Sorenson,et al.  Bilateral lesions of the amygdala attenuate analgesia induced by diverse environmental challenges , 1994, Brain Research.

[5]  M. Davis,et al.  Involvement of the central nucleus and basolateral complex of the amygdala in fear conditioning measured with fear-potentiated startle in rats trained concurrently with auditory and visual conditioned stimuli , 1995, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[6]  J. Besson,et al.  Intravenous morphine depresses the transmission of noxious messages to the nucleus centralis of the amygdala. , 1993, European journal of pharmacology.

[7]  K. Koyano,et al.  Effects of synthetic ω-conotoxin on synaptic transmission , 1987 .

[8]  C. A. Marsden,et al.  Central C-Fos Expression Following 20kHz/Ultrasound Induced Defence Behaviour in the Rat , 1997, Brain Research Bulletin.

[9]  B. Roozendaal,et al.  Central amygdala lesions affect behavioral and autonomic balance during stress in rats , 1991, Physiology & Behavior.

[10]  J. Ramachandran,et al.  Antagonists of neuronal calcium channels: structure, function, and therapeutic implications. , 1995, Annual review of pharmacology and toxicology.

[11]  G. Koob,et al.  Opiate Withdrawal-Induced Fos Immunoreactivity in the Rat Extended Amygdala Parallels the Development of Conditioned Place Aversion , 2001, Neuropsychopharmacology.

[12]  J. Besson,et al.  A possible spino (trigemino)-ponto-amygdaloid pathway for pain , 1989, Neuroscience Letters.

[13]  F. Helmstetter,et al.  The amygdala is essential for the expression of conditional hypoalgesia. , 1992, Behavioral neuroscience.

[14]  T. Coderre,et al.  Optimal scoring strategies and weights for the formalin test in rats , 1997, Pain.

[15]  P. Coffin,et al.  Anatomical basis for cannabinoid-induced antinociception as revealed by intracerebral microinjections , 1999, Brain Research.

[16]  S. Maier,et al.  The amygdala is necessary for the expression of conditioned but not unconditioned analgesia. , 1993, Behavioral neuroscience.

[17]  G Paxinos,et al.  The rat brain in stereotaxic coordinates: Computer graphics files. , 1997 .

[18]  Joseph E LeDoux,et al.  Different lateral amygdala outputs mediate reactions and actions elicited by a fear-arousing stimulus , 2000, Nature Neuroscience.

[19]  B. H. Manning.  A Lateralized Deficit in Morphine Antinociception after Unilateral Inactivation of the Central Amygdala , 1998, The Journal of Neuroscience.

[20]  J M Besson,et al.  Nucleus centralis of the amygdala and the globus pallidus ventralis: electrophysiological evidence for an involvement in pain processes. , 1992, Journal of neurophysiology.

[21]  S. Ohtori,et al.  Fos Expression in the Rat Brain and Spinal Cord Evoked by Noxious Stimulation to Low Back Muscle and Skin , 2000, Spine.

[22]  Michael Davis,et al.  Induction of the c-fos proto-oncogene in rat amygdala during unconditioned and conditioned fear , 1991, Brain Research.

[23]  Michael Davis,et al.  Double Dissociation between the Involvement of the Bed Nucleus of the Stria Terminalis and the Central Nucleus of the Amygdala in Startle Increases Produced by Conditioned versus Unconditioned Fear , 1997, The Journal of Neuroscience.

[24]  R. Burstein,et al.  Retrograde labeling of neurons in the spinal cord that project directly to the amygdala or the orbital cortex in the rat , 1993, The Journal of comparative neurology.